The ocean is more than a great place to catch fish

December 11, 2009

Pacific right whale. (Credit: Laurie Murison)

By David Suzuki with Faisal Moola

To many people, our oceans are little more than a great blue expanse of water. To some, they are a source of beauty and enjoyment. And for millions of people around the globe, the oceans are sources of food and jobs in fishing or fish-farming industries. But the oceans are also the anchor for life on this planet. When it comes to global warming, the oceans may be our salvation.

The oceans do much more than provide us with food, employment, and enjoyment. They also absorb much of the excess carbon that humans have been pumping into the atmosphere during industrialization.

The world's oceans have already absorbed a huge percentage of carbon that would contribute to global warming if it were released into the atmosphere, according to Blue Carbon: the Role of Healthy Oceans in Binding Carbon, a report by the UN Environment Programme, the UN Food and Agriculture Organization, and the Intergovernmental Oceanographic Commission of UNESCO.

The IOC's Patricio Bernal argues that "the ocean has already spared us from dangerous climate change." He adds, though, that "each day we are essentially dumping 25 million tons of carbon into the ocean. As a consequence, the ocean is turning more acidic, posing a huge threat to organisms with calcareous structures." (These organisms include corals, clams, shrimp, and many types of plankton.)

The report finds that protecting and restoring marine ecosystems such as estuaries and mangroves could contribute to offsetting up to seven per cent of current fossil fuel emissions at a much lower cost than technologies to capture and store carbon at power stations. What this means from a global warming perspective is that by simply protecting and restoring these ecosystems, we could achieve 10 per cent of the reductions required to keep the climate from warming by 2º C. These actions would also have numerous other benefits to marine wildlife and fisheries.

The damage we are inflicting on ocean ecosystems has numerous consequences for global warming. Ice at the North and South poles has kept our ocean temperatures relatively stable for millennia. Now, our oceans are absorbing so much additional energy that the ice is melting and the oceans are warming at an ever-increasing rate. If polar ice disappears, the warming trend will escalate because the albedo effect, the reflection of sunlight off bright surfaces like clouds and ice, will decrease. We can only guess how this will affect marine ecosystems and all life on our planet, but we are already noticing changes in the distribution and abundance of species throughout the world's oceans.

The Blue Carbon report notes that of all living organisms that are able to capture carbon, those that live in the ocean capture more than 55 per cent. Coastal wetlands, marshes, mangroves, and estuaries play an important role in absorbing carbon from the atmosphere. Other life forms in the open ocean assimilate carbon through their diets, which is then stored in the sediments of the deep ocean when the life forms die and sink to the bottom. This carbon will be stored for millennia.

Protecting more of these valuable ocean ecosystems will help control climate change resulting from excess carbon in the atmosphere and will also help restore the capacity of these areas to support marine life, particularly fish. Given that over three billion people depend on marine fish for protein, we should do all we can to ensure abundant fisheries for the future.

Canada can play major role on this issue. We must protect the valuable ocean ecosystems within Canada's jurisdiction and we must be a global advocate to set objectives for conserving and managing the Earth's marine resources.

We have tremendous opportunities in Canada to do our share. The coastal estuaries and sea grasses on Canada's West Coast and the great delta of the Mackenzie River are just two of many places where our government could do a lot more to ensure protection and recovery of these environments.

The need for additional conservation of our oceans is undeniable, the benefits of doing so are becoming more evident every day, and the opportunity is before us. All we need now is for governments to acknowledge the leading science, like that presented in the Blue Carbon report, and to get serious about investing in strategies that will put us on a more sustainable path.